Wiki info about Spitfire Mk Vc/trop

A single-seat, single-engine all-metal monoplane fighter, this variant of the Spitfire Mk V was fitted with the new Type C “universal” wing, capable of being fitted with a variety of armaments. The Mk VC could be fitted with four 20mm Hispano cannons, or it could carry two 20mm Hispano cannons and four 0.303 inch Colt-Browning Mk II machine guns. The cannons in the type C wings had a tape supply and so could carry up to 120 rounds per gun, unlike the type B wings, which were limited to 60 rounds. In addition, the Mk VC had other modifications to the airframe such as a strengthened fuselage, more armor, larger oil cooler and a new windscreen design.
Production of the Mk VC variant began in October of 1941, with the first aircraft being equipped with a Rolls Royce Merlin 45 or 46. However, with the appearance of the German Focke-Wulf FW190 fighter, Spitfire pilots found themselves being outmanoeuvred at low and medium altitudes.
The Mk VC was then fitted with Merlin 50, 50A, 55, and 56 engines. To improve performance characteristics at low and medium altitudes, some of these engines were fitted with a cropped supercharger impeller to allow maximum power to be reached at lower altitudes. Engines designed this way included the 45M, 50M, and 55M.
On the lower altitude models, further changes were implemented. To reduce drag and moment of inertia on the aircraft's longitudinal axis, the wingspan was reduced and the elliptical wingtips were redesigned to be nearly rectangular. Fighters designed with low-altitude combat in mind were designated Spitfire LFMk Vs (Low Flight). Aircraft optimized for mid-altitude combat were designated Spitfire FMk Vs (Flight) and fighters fitted with the Merlin 46, 50A, or 56 were designated Spitfire HFMk Vs (High Flight) and had an increased wingspan with elongated, elliptical wingtips.
The Spitfire VC fought in all theatres in which the RAF was active from 1941 to 1944. A total of some 6,500 Spitfire Mk V fighters were produced, of which 2,467 were Mk VCs.